Synbiotics refer to nutritional supplements combining probiotics and prebiotics in a form of synergism, hence synbiotics. The synbiotics concept was first introduced as " mixtures of probiotics and prebiotics that beneficially affect the host by improving
the survival and implantation of live microbial dietary supplements in the gastrointestinal tract by stimulating the growth and/or by activiating the metabolism of one or limited number of health promoting bacteria thus improving host welfare."
are live bacteria which are intended to colonise the large intestine and confer physiological health benefits to the host. A prebiotic is a food or dietary supplement product that confers a health benefits to the host associated with modulating the microbiota.
Prebiotics are not drugs, not functioning because of absorption of the component, not due to the component acting directly on the host, and are due to changes to the resident bacteria - either changing the proportions of the resident bacteria or the activities
thereof. Measurable changes to the microbiota in the absence of a desirable physiological consequence in the host does not qualify as a prebiotic. A prebiotic may be fibre but a fibre is not necessarily a prebiotic. Cr: Wikipedia